The present invention is directed to a device for measuring the height of a person, and has especial, but not limited, use to the measurement of the height of children and elderly persons suffering from osteoporosis. In U.S. Pat. No. 4,694,581 which is incorporated by reference herein, there is disclosed a height-measuring device in which there are provided a vertical scale-part that is used for measuring the height of child or adult. Connected to this scale-part is a mounting part by which the unit is vertically fastened to a wall. Also provided is a vertically slidable indicator part that is placed on the person's head and used to indicate on the vertical scale-part the height being measured. However, owing to the bulk of construction, this prior-art height-measuring device is costly to ship. Furthermore, when mounting this height-measuring device to a wall, the bottom edge-surface of the scale-section must be located a specific distance above the floor, which distance is that measurement at which the lower end of the scale-section starts; for example, since children that are able to stand are more than two feet tall, the scale-section will start with the measurement of twenty-four inches. Therefore, the bottom edge-surface of the scale-section must be located exactly twenty-four inches above the floor. Even though the fastening of the height-measuring device is performed only once, at the time of initial installation, this can be exacting task, and one that may be done incorrectly, if the installer of the height-measuring device is not careful.